Coaxal Cable In My New Van?????????????

[Ian_374329537]

Hi All,

I have a good question for you all, on my new ace award nightstar it has a coaxal input in the battery box, great idea I hear you say yes it is but when you connect to a sat. dish with another length of coaxal cable you get no signal in the van. I have had this same problem in my house, it is down to the different grades of coaxal cables, if they do not match they will not work, does anyone know what grade the cable is in these van's so I can match it up rather than dragging cable through window.

I know this is very technical but im sure someone somewhere will have the awnser.

Many Thanks,

Ian.

 

[RogerL]

Satellite cable is different to conventional analogue tv coaxial, including better screening. Digital tv needs better screening than analogue so most cabling specific to digital tv is done using satellite cable as it's readily available.

I suspect that if you want to use the connection for a satellite dish you'll need to replace the cable to get the correct grade.

 

[Rod_5041370]

CT100

 

[Ian_374329537]

Hi Rod,

Is this the cable that is in the van. ct100.

Do you know how many other version there are, I presume it will be marked on the sleeve.

Ian.

 

[rob_jax]

Ian,

TV and satellite cable should have the same resistance to AC signals (impedance) and there are really four classes of 75 Ohm cable:

Type A and Type B (the expensive stuff) - known as copper on copper - the central conductor is insulated with either a white "expanded foam" dielectric insulator or an air-gap insulator, then shielded with a solid copper foil and this is covered with a good quality copper braid. It's expensive, but in terms of satellite signal transmission it's more than ten times as good as the next type:

Type C - uses the air-spaced insulator, but wrapped in much cheaper "silver foil" and a thin copper braid. Cheaper construction and much lower quality - the copper central connector is not bonded to the insulator and it's quite common for the conductor to more and break connection... But in terms of signal transmission, it's a good 50 times better than:

Type D - which uses a think copper braid - looks like a comb-over rather than a full head of hair - over the insulator. Cheap, nasty and to be avoided.

But for TV transmissions in the UHF (500 to 900MHz) band, the signal loss is not too great even with type D - so that's what gets fitted - and yes Type A or B is much better, but most people might not notice any difference.

But for satellite transmissions in the GigaHertz frequencies - then signal loss with the wrong cable is an issue - and only the best cable will do.

Note: Having said all that, we don't have satellite TV at home, nor any TV on our caravan - but my company does build process control analysers for refineries - and we use a lot of Type B 50 Ohm cable for long distance signal networking.

Robert

 

[Ian_374329537]

Hi rob_jax

I guess from what you are saying if I try to connect a Type A to a Type D I will have problems, I think this is what's happening, I have just looked at the dish cable and that is ph100 and I see from a earlier post that ct100 maybe in the van, I presume this is where I am getting the problems with comaptability.

Ian

 

[rob_jax]

And I should have said CT100 is one brand name for Type A cable - but all the supplies know what you mean if you ask for CT100.

WF100 has the white foam insulator - but the same specification for shielding and braid.

And don't forget you'll need the connectors too - because those will also affect signal transmission...

 

[Ian_374329537]

Hi,

What type is ph100 if ct100 is type A, and would this cause the conflict im having.

Thanks,

Ian

 

[rob_jax]

Hi,

What type is ph100 if ct100 is type A, and would this cause the conflict im having.

Thanks,

Ian

PH100 (or maybe PF100) should be OK - it's a WF100 cable (white foam insulator - type A/B) made by Philex - and they've done the honourable thing and not used another companies trademark...

But the only way to be 100% sure is to undo an easy to access connector - and look at the cable. If it has a solid central connector, white foam (or air gap) insulator, then a double layer of copper tape and copper braid - then it's the top specification stuff.

If it's only got a comb-over copper braid - then it's junk grade.

And check your satellite cable too - it should all be Type A/B - and good quality connectors.

And if you are looking at the connectors - just make sure that no one has bridged the connector with a loose bit of braid...

 

[rob_jax]

Ian,

I see some posts have crossed.

1. Your P100 satellite cable is OK

2. I'd be (pleasantly) surprised if the cable in the caravan was CT100 / WF100 / PH100 - call me a cynic but I'd guess it was type D (so-called low loss TV cable) - every metre of Type D cable will be like adding in an extra 50 metres of Type A/B

3. And I would certainly use a multi-meter to check for a short in the caravan cable

4. And if your caravan has a Status aerial, I'd also make sure that the cable you want to use DOESN'T go to the Status amplifier - that will totally filter out satellite frequencies...

 

[Rod_5041370]

I don't believe that I can add much to Rob's posts except to reinforce his view that it is unlikely that a UK caravan manufacturer will have used CT100 (my German maker has).

I would advise that you replace all the cable with CT100 or equivalent Type A and if you need to use a connector, use a proper "F" type.

There can be considerable signal loss across connectors, even when correctly installed.

 

[Rod_5041370]

I don't believe that I can add much to Rob's posts except to reinforce his view that it is unlikely that a UK caravan manufacturer will have used CT100 (my German maker has).

I would advise that you replace all the cable with CT100 or equivalent Type A and if you need to use a connector, use a proper "F" type.

There can be considerable signal loss across connectors, even when correctly installed.

Also, you should try to go from the Sat dish direct to the digital receiver with as few connectors etc. as possible.